Method of and apparatus for handling ash



June 14,- 1932. F. B. ALLEN METHOD OF AND APPARATUS FOR HANDLING ASH Filed May 1'7, 1928 2 Sheets-Sheet 1 INVENTOR 2 Jana/54 L450 ATT RNEY June 14, 1932. F. B. ALLEN 1,363,218

METHOD OF AND APPARATUS FOR HANDLING ASH Filed May 17, 1928 2 Sheets-Sheet 2 xaik INVENTOR M /o MA. BY

ATT RNEY Patented June 14, 1932 OI PENNSYLVANIA METHOD OF AND APPARATUS FOR HANDLING ASE Application filed May 17,

This invention relates to a new and improved method of handling incombustible residues resulting from the combustion of powdered fuel and to new andimproved apparatus for pract'cing such method.

The burning of powdered fuel, prior to my present invention and so far as I am aware, has been carried out by three general methods. The first method consisted of extracting heat from the falling incombustible residues by means of a screen of water tubes extending across the combustion chamber and then collecting the residues below the screen for periodical removal. This. method is objectionable because the tubes congeal the molten slag in the residues and quickly acquire a layer of solidified slag and ash on the tops thereof which often bridge across to adjacent tubes and which must be removed. Frequently increasing amounts of ash build up thereon and correspondingly decrease the efficiency of the screen. The ash which passes thru the screen agglomerates in large masse which adhere to the refractory lining of the furnace and must be broken away from the lining and reduced to sizes which can be subsequently handled readily.

he second method consisted in usin a Water cooled furnace bottom or combustlon amber and a hopper associated therewith into which the incombustible residues can fall and in which they cool, forming large agglomerates which adhere to the closure of the hopper discharge opening and to the lining of the side of the hopper. The same difliculty in handling such ash is encountered in the method as in the first method.

e third method consisted in using a combustion chamber having a hopper associated therewith into which the uncooled ash fell and accumulated and in which it was then quenched with water. Since the walls of the combustion chamber were not artificial] cooled, the ash was very highly heated when it reached the hopper. the slag congealed on the linings of the hopper and its closure and formed large agglomerates and, when quenched, the linings were subjected to high breakage losses and the solidified ash was diflicult to remove. The

per walls and before it can form large The result was that,

1928. Serial No. 278,609.

lining of the combustion chamber walls was also of short life becaues of the high temperature of the flame and slag.

I have devised a method which avoids these several disadvantages. It results in the preservation of the combustion chamber linings with coincident extraction of the heat from the ash to a point somewhat above the congealing point of the molten slag therein thus transferring heat from the slag to the boiler water while ensuring against solidification of the slag in the combustion chamber or adherence to the walls thereof. My method also results in the preservation of the hopper walls due to quenching the reviously somewhat cooled ash while it is alling and before it can agglomerate in large masses or adhere to the hopper walls. This insures easy opening of the closure. This method also disintegrates the ash into finely divided condition which can be removed from the hopper and conducted to a place of disposal substantially without the use of any hand labor.

Briefly my method consists in burning powdered fuel in a combustion chamber having its walls cooled by the boiler water which cooling can be so regulated as to cool but not to congeal the slag or molten material in the ash or incombustible residues; in letting the residues fall freely from the-combustion zone into a hopper which is maintained at a much lower temperature than the combustion zone and in spraying the ash, while it is falling in the hopper, with water thereby congealing and disintegrating the slag and ash before it can touch or adhere to the hopglomerates.

The new and improved ap aratus described and shown herein and especially adapted for practicing the herein described method possesses-the outstanding features that the combustion chamber has controllably cooled water-tube walls, and is in open communication thru a. restricted passage with an ash hopper; that no slag congealln obstruction is interposed in the path 0% the freely falling ash; that the combustion chamber walls extract heat from the falling ash approaching but not in excess of the congealing temperature of the molten slag in the ash; that the falling ash is quickly quenched to below its congealing temperature in the hopper before it can adhere to the hopper walls or form large solidified masses or agglomerates; that the refractory lming of the combustion chamber and hopper has a long life and requires correspondingly small malntenance'expense because little or no slag solidifies thereon which requires manual removal. D

Referring particularly to the drawings in which one embodiment of my invention is shown,

Fi 1 is a transverse section of a powdered fuel urning furnace embodying my invention Fig. 2 is a longitudinal sectional view taken on the line 2-2 of Fig. 1.

I In the embodiment shown, the device comprises a furnace bottom or combustion chamher having substantially vertically extending end water walls and downwardly converging side water walls which define the sides of the open passage connecting the -chamber andhopper. The side walls comprise the supporting frames A which converge downwardly at an angle greater than the angle of repose of solid material, and then curve laterally away from each other as at 1 and form the top walls of the hopper. The end and side walls comprise an inner refractory lining B, an outer supporting frame and a plurality of water tubes or pipes connected to headers 2 at the lower ends. and to similar headers or to the boiler at the 11pper ends. Suitable valves 3 are provided to regulate the flow of water in the tubes C and thereby to control the extent of cooling 9 of ash by the tubes and walls.

A hopper is disposed beneath the combustion chamber in substantially fluid tight communication therewith. The hopper comprises the downwardly converging side walls 4;; composed of the metallic frame 4 and the re fractor lining 5. In the preferred embodiment the side walls are entirely overhung by the laterally extending parts of the side walls of the combustion chamber. The end walls of the hopper are substantially vertical continuations of the end walls of the combustion chamber and comprise the metal frame 6 which supports the lining 7 of refractory inaterial. 7 5;; S ray devices or quenchers are disposed in the side walls of the hopper. Each spray device has a nozzle 8 (see Fig. 2) which opens inwardly into the hopper preferably adjacent the upper portion thereof thru which liquid from an exterior supply is continuously sprayed thru the incombustible residues" as they fall from the chamber into the hopper. The spray devices lie under the bend of the side walls of the combustion chamber, whereby they are shielded from the falling residues C the and the intense heat of the combustion chamber. If desired, spray devices can be provided in the end walls of the hopper. The bottom of the hopper is provided with a plurality of transversely extending crickets 9 which engage the side walls and cooperate therewith to direct the combustion residues toward a plurality of dischar e openings which arenormally closed by t e gates 10. Poke doors 11 are provided in the end and side walls of the hopper.

Chambers areprovided beneath each pair of discharge openings of the hopper to receive the combustion residues and direct the same into a conduit. Each chamber comprises the side'ia'nd end walls 12 which carry downwardly'inclined feed plates 13 which terminate above a grate. posited on the plates when the doors are opened are flushed therefrom by water from nozzles, or'otherwise removed.

The combustion residues pass from the feed plates through a grate 14 into a conduit 15 which extends longitudinally of the furnace. Swiftly flowing fluid means such as a jet of water from a nozzle 16 are provided in the conduit for conducting the mixture of ash and water through the conduit.

In the operation of the device powdered fuel is ignited and burned at high temperature in the combustion chamber and the incombustible residues fall through the lower portion of the combustion chamber and thru assage into the hopper. As they fall the resi ues and the gas surrounding the same are cooled by the cooling influence of the water walls of the combustion chamber and also by direct contact therewith but to an extent insufiicient to congeal the molten portion of the residues. A considerable part of the residues from the burned powdered fuel, both molten and solid drop down onto the downwardly inclined water cooled walls of the combustion chamber. The molten particles which strike these walls run together and down over the surface of the walls until they drop through the opening into the hopper. As they pass over the walls they are cooled but not to such a degree that the molten material becomes solidified. As the cooled residues fall into the hopper they encounter the spray of water which almost instantly disintegrates and congeals the molten parts and cools the solids to an extent suflicient to prevent agglomeration into large masses or adherence to the hopper walls. The entirely solidified resi-- dues accumulate in the hopper as small particles which do not adhere to the hopper walls. I The gates 10 are withdrawn from the discharge openings of the hopperat intervals. The relatively finely divided residues fall upon the feed plates and are flushed therefrom into the conduit 15 through which they are conducted to a place of disposal.

It will be understood that the quenchers The residues de- Ill quenchers congeal they contact with The linings of both combustion chambers and hoppers are thus pro tected and their life prolonged.

ile a particular embodiment of the invention has been shown and described it is apparent that numerous modifications can be made therein without departing from the spirit of the invention, and it is not desired to limit the same otherwise than is indicated in the accompanying claims:

The new and improved method of handling incombustible residues resulting from the combustion of powdered fuel which comprises burning powdered fuel in a combustion zone from which the incombustible residues may fall freely during the burning of the fuel, extracting heat from the falling residues in the combustion chamber without congealing molten material therein, cooling the falling residues to below the congealing temperature of molten material therein after the residues have passed out of the combustion zone, and finally removing the cooled residues to a place of disposal.

The new and improved method of handling incombustible residues resulting from the combustion of powdered fuel which comprises burning powdered fuel in a comustion zone from which the incombustible residues may fall freely-during the burning of the fuel, extracting heat from the falling residues in the combustion chamber without congealing molten material therein, quenching the falling residues to below the congealing temperature of molten material therein after the residues have passed out of the combustion zone, and finally removing the cooled residues to a place of disposal.

3. The new and improved method of handling incombustible residues resulting from the combustion of powdered fuel which comprises burning powdered fuel in a combustion zone from which the incombustible residues may fall ffeely during the burning of the fuel. extracting heat from the residues the combustion chamber without congealmg molten material therein. suddenly congealing and disintegrating the molten material of the residues after the residues have passed out of the combustion zone. and finally remolving the cooled residues to a place of disosa v p 4. The new and improved method of handling incombustible residues resulting from the combustion of powdered fuel which comprises burning powdered fuel in a combustion zone from which the incombustible residues may fall freely during the burning of the fuel, extracting heat from the residues in the combustion chamber without congealing molten material therein, spraying the falling residues after they have passed out of the combustion zone with water thereby quenching and disintegrating the same, and finally removing the cooled residues to a place of disposal.

5. Apparatus of the class described comprising in combination a powdered fuel burning furnace having a combustion chamber in which fuel may be burned and provided with an opening in its bottom portion, said combustion chamber having downwardly converging walls provided with cooling tubes therein, a hopper positioned below said openmg to receive incombustible residues of combustion as such residues fall from the said combustion chamber thru said opening, means to spray cooling fluid on said residues while they are falling thru the hopper, means to retain the cooled residues in the hopper, and means for periodically removing such cooled residues to a place of disposal.

6. Apparatus of the class described comprising a combustion chamber having downwardly converging walls provided with cooling fluid tubes therein, a hopper below the chamber and in open communication therewith to receive incombustible residues falling from the chamber to the hopper, means in the hopper for spraying cooling liquid on incombustible residues as they fall in to the hopper, means for collecting said cooled residues in the hopper and means for removing the residues to a place of disposal.

7. Powdered fuel burning apparatus comprising in combination. a combustion chamber having a restricted bottom opening formed in part by oppositely disposed, converging, downwardly extending, controllablv cooled side walls, a hopper disposed beneath the said chamber and having walls joining the chamber walls in fluid tight relation, the hopper having a top opening of greater width than the width of the bottom opening of the chamber. certain walls of the hopper being provided with cooling fluid quenchers to spray ash falling in the hopper from the combustion chamber, and means for periodically removing the accumulated ash from the hopper.

8. Powdered fuel burning apparatus comprising in combination, a combustion chamber having a restricted bottom opening formed in part by oppositely disposed, converging. downwardly extending controllably cooled side walls, a hopper disposed beneath the said chamber and having wallsjoining the chamber walls in fluid tight relation, the hopper having a top opening of greater width than the width of the bottom opening of the chamber, certain walls of the hopper being provided with cooling fluid quenchers to spray liquid ash falling in the hopper from the combustion chamber, and means including a sluiceway for discharging the accumulated ash into the sluiceway in small quantities. r

9. Powdered fuel burning apparatus comprising in combination an open bottom combustionchamber having water cooled walls, certain of the walls being oppositely disposed and extending convergingly downward and then diverging outward and forming a restricted bottom opening, a hopper having a controllably closed opening in its lower por- 1 tion and upwardly extending walls joined in fluid tight relation to the said outwardly diverging walls remote from the said restricted bottom opening, means in the hopper for spraying quenching fluid on ash falling in the hopper from the said chamber, and means including a sluiceway for removing the ash and quenching liquid from the hopper.

10. Powdered fuel burning apparatus comprising in combination a hopper having upstanding side walls and provided with a controllably closed discharge opening in its lower portion and an open top, a combustion chamber disposed above the hopper and having opposite upwardly diverging walls spaced apart to provide an open passage into the hopper, the said walls being extended outwardly from the passage to the adjacent hopper side walls and overlying the hopper, the walls of the hopper chamber being joined in substantially fluid tight relation, liquid sprayer-s in the hopper side walls, and fluid cooling means in the combustion chamber walls.

In testimony whereof I hereunto aflix my signature this 3rd day of May, 1928.

FRANK B. ALLEN. 

